Device for eliminating means of combat

ABSTRACT

To remove means of combat such as mines and unexploded ordnance increasing use is made of hollow charges. Inherent in these is the risk of triggering premature ignition since their liners contain metals. According to the invention a hollow charge ( 4 ) suitable for eliminating means of combat is configured largely free of metals and has a liner ( 3 ) made of an electrically non-conductive, amorphous material. The material of choice is glass, which when configured correspondingly in addition has a projectile-forming effect and thus raises penetration capability. Apart from lowering environmental pollution the use of metal-free devices also eliminates false alarm messages in metal detectors during mine clearance and therefore significantly improves the safety of mine clearance personnel. The support ( 16 ) carrying the hollow charge ( 4 ) is fitted with a ball joint ( 13, 14 ), resulting in high adaptability to the place of use and type of combat means (M) concerned.

The present invention relates to a piece of ammunition having adentonator in a plastic housing containing a hollow charge for use inthe disposal/destruction of explosive objects.

BACKGROUND OF THE INVENTION

The declared aim of numerous countries and humanitarian organizations isto clear the countless minefields scattered over the globe and todispose of the unexploded bombs still to be found in all former theatresof war.

The earlier practice of detonating mines and unexploded bombs by meansof other weapons has proved to be highly dangerous and often alsoineffective. Continuing development and the use of proximity fuses,vibration fuses and fuses responding to magnetic-field changes makes theclearing of mines immensely more difficult and increases the costimmeasurably.

Devices of the present general type (DE-C1-36 23 240) and employ a “loworder” technique, i.e. the piercing power of a blast—forming hollowcharge mounted e.g. on a tripod is adapted to the casing of the piece ofammunition to be disarmed so that the hollow charge pierces the latterin a controlled manner without initiating it. In this way, the piece ofammunition can be disposed of relatively safely by removal of theexplosive charge or by combustion thereof.

However, the necessary adaptation of the piercing power is problematicbecause this can only be done empirically, either by means of differentcharges or, as known from DE-C1-36 23 240, by the selective attachmentof metal (in practice brass) components reducing the blasting power.Although the known device has a relatively low metal content, a furthermetal is introduced into the system by way of the attached component inaddition to the metal lining, which can cause the piece of ammunition todetonate when modern detonators are brought close and, at least in thecase of relatively large minefields, causes lasting damage to the soilby burdening it with heavy metals. In addition, the expense of clearing,often in locations which are accessible only with difficulty, is greatowing to the necessary adaptation of the blasting power to the object tobe cleared and requires additional logistics.

GB-A-2 254 402 discloses a cutting charge encapsulated in a plastichousing so as to be water-tight and designed principally formarine-technology applications. The lining used is the preferred liningand comprises a ductile, high-density material such as copper. However,the also mentioned possibility of using plastic, ceramic or glass is atthe same time rejected because these have the tendency to pulverize ondetonation. Owing to its linear cutting blast, a cutting charge isfundamentally unsuitable for the disposal of weapons: its piercing poweris too low.

A break-up charge (AT-B-398 634) with a tripod for simplified verticalpositioning of the charge has insertion openings in which rod-type feetof various lengths are held by friction. The disadvantage is that theangular position of the break-up charge is not adjustable, with theresult that the effectiveness of the charge is at the very leastimpaired, depending on the ground and the size of the piece ofammunition to be destroyed.

An improved tripod is described in U.S. Pat. No. 5,210,368. The heightof this tripod can be adjusted so that the detonator of the piece ofammunition to be destroyed can be triggered by remote control. Therelatively low height above the ground and the limited rotatabilityrelative to the respective horizontal plane prevents its use inaccordance with the low order technique.

U.S. Pat. No. 5,301,594 discloses a stationary machine for disarmingunexploded bombs, for sampling and sealing. This machine is entirelyunsuitable for field use, in particular for clearing mines.

A device according to DE-A1-195 14 122 is suitable for detonating aplurality of objects with simultaneous or sequential, centraldetonation. This device requires blasting charges to be fixed to theweapon to be destroyed, which in a good many cases is too dangerous andin particular unsuitable for clearing minefields, etc.

With weapons disposal systems or EOD (explosive ordnance disposalsystems), there is always the danger of premature triggering duringinstallation in the area of the mines, e.g. caused by the reaction ofelectromagnetic sensors contained in mines, by the metal parts in theEOD and/or by resulting field changes, in particular by movement ofexplosive charges with inserted metal linings.

These linings, in particular when they comprise heavy metals,additionally cause further emissions, especially in areas with a highdensity of mines, and harm the fauna, flora, soil, ground water andsurface water quite considerably and permanently.

Surprisingly, a projectile-forming hollow charge with such an amorphous,non-electrically conductive lining can safely detonate mines andunexploded bombs up to a distance of several meters or at least makethem safe.

The subject of the invention is advantageously aimed at the target(weapon) by the means attached to a cover and/or the housing, althoughthe actual alignment is carried out by known mechanical and/or opticaldevices.

It has been shown that low levels of energy are adequate for weaponsdisposal, namely because in most cases it is sufficient to pierce thehousing and/or the detonating chain of the dangerous piece of ammunitionby means of a hollow charge rather than having to detonate or at leastdeflagrate it, as previously thought.

On the basis of this knowledge, relatively large weapons can also bedisposed of with little technical and financial expenditure, i.e. can bemade safe to the extent that they can be safely destroyed, for exampleby subsequent controlled combustion.

On the basis of current knowledge, technical glass and also organicglass, ceramics, in particular aluminium oxide, and numerous plasticswith relatively high density, such as polytetrafluoroethylene andpolypropylene, are suitable as materials for the linings. The concept ofa non-electrically conductive, amorphous material, i.e. an electricalnon-conductor, also includes glass mixtures to which metals or metaloxides have been added to an extent that the glasses remainnon-conductive and consequently are not detected by conventional metaldetectors used for mines and do not trigger the latter.

It has been shown that the effectiveness of amorphous linings isincreased by their formation as a projectile-forming charge.

A cup-shaped formation of the lining produces a shaping process duringthe first 15 cm of its flight, corresponding to an almost ideal shape ofa projectile and achieving an extensive piercing effect in the target.

For technical and economical reasons, a lining of glass is preferred.

Linings of ceramic, in particular A1 ₂O₃, have also been tested, butthese are uneconomical to manufacture owing to the necessary sinteringprocess and the required finishing process (grinding). The arrangementof a ball-and-socket joint enables the hollow charge to be aimed at thetarget in the simplest manner.

A support which further increases the versatility of the EOD has provedsuccessful. By means of selectively insertable supporting rods, theheight of the EOD can be fixed within broad limits. Predeterminedbreaking points permit simple adjustment of the supporting rods to thedesired height and additionally bring about the desired “disintegration”of the rods on detonation.

The incorporation of supporting ribs inside the housing allows the EODto be placed directly on the weapon to be destroyed and additionallyprovides mechanically satisfactory centering of the lining.

The EOD can be assembled particularly easily by means of the structuralarrangement comprising an annular groove. A tapered annular grooveproduces a clamping effect which further simplifies assembly.

The insertion of a detonator into a hollow cylinder is particularlyadvantageous.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be further described in the followingwith reference to drawings, wherein:

FIG. 1 shows a sectional view of a hollow charge for clearing mines;

FIG. 2 shows an attachment for pyrotechnically initiated detonation ofthe hollow charge according to FIG. 1;

During the clearing of minefields, it has also repeatedly beendemonstrated that these heavy metals, even after detonation of themines, initiate mine detectors and thus cause indication errors.Consequently, the recognition rate during clearing is reduced. As aresult, the safety of the mine-clearing personnel is enormously reducedon top of the non-eliminable danger.

Therefore, the object of the present invention is to provide a safelyoperating device for the disposal of weapons, which does not have theaforementioned disadvantages, is metal-free and allows accuratedestruction at a distance from the weapon, i.e. simplified disposal. TheEODs to be provided must not contain any substances which could alsocause substantial harm to the environment.

At the same time, the subject of the invention must serve to dispose ofexplosive devices which are not identifiable, for example for reasons ofsafety. Unexploded bombs must also be detonated safely and in anenvironmentally-friendly manner and not cause indication errors duringmine clearing.

Furthermore, it must be possible to manufacture the device in largebatches as inexpensively as possible using known, modern manufacturingmeans.

The support carrying an EOD must have a high level of adaptability tothe site of use and the type of weapon and must also be metal-free.

Moreover, all the materials used should have low relative pernittivityso as not to trigger sensitive electronic sensors responding to generalfield changes.

FIG. 3 shows a side view of an electrically initiated hollow charge forthe detonation of an unexploded bomb;

BRIEF DESCRIPTION OF THE INVENTION

The objects are achieved by a disposal device of the present inventionin the form of a piece of ammunition having a detonator in a plasticshousing containing a hollow charge, a lining thereof being supported inthe housing, wherein the lining is formed as a projectile-forming chargeand comprises a non-electrically conductive amorphous material.

FIG. 4 shows a support with the hollow charge in two schematically shownpositions for the disposal of weapons;

FIG. 5 shows a sectional view of a hollow charge having aprojectile-forming lining, and

FIG. 6 shows a sequential, schematic representation of the projectileformation of the lining according to FIG. 5.

In all the figures, like reference numerals are used for like functionalparts.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, a plastics housing 1 contains an explosive charge 2 having aconically shaped lining 3 made of glass. The hollow charge 4 thus formedis closed by a cover 5 likewise made of plastics and provided with anannular groove 17 frictionally holding the cylindrical edge of thehousing 1. A hollow cylindrical attachment 27, which is covered by acentrally slotted protective cap 20, is arranged above the cover 5 inthe axial direction.

A ball support 12 projects from one side of the cover 5 and holds a ball13 for its part partially enclosed by a socket 14, thereby forming aball-and-socket joint. The socket 14 merges into a connecting sleeve 15,into which is inserted a rod 16.

Supporting ribs 18, on which the lining 3 is supported at the front end,can be seen in the lower part of the housing 1. The spherical cup of thehousing 1 has a frontal predetermined breaking point 19 in the form of arecess.

The blast direction of the hollow charge is designated by S, theschematically shown mine by M.

Initiation I of the EOD according to FIG. 1 is carried out by insertinga sleeve-type detonating tube 7 of a detonator 28 according to FIG. 2into the slotted protective cap 20 of the hollow cylindrical attachment27. The cavities in the detonator 28 and the detonating tube 7 arefilled with a conventional secondary explosive such as hexogen oroctogen and drive the detonation axially symmetrically into theexplosive charge 2.

Above the detonating tube 7 is arranged a known detonating capsule 6which is laterally held and secured in the detonator housing 8.

The hollow charge 4 according to FIG. 1 is initiated by inserting adetonating fuse into two opposing lateral recesses 8 a in the detonatorhousing 8. For this purpose, a strap 11 is pulled away from a nipple 11a, and a cover 9 fixed to a bending strap 10 is opened. After thedetonating fuse has been introduced, the cover 9 is closed and the strap11 is drawn over the nipple 11 a and thereby secured.

A similar hollow charge 4 is aimed at a bomb B in FIG. 3, although inthis case an electrical detonating cable 29 with an electric igniter 29a at the end is connected to a remotely placed detonation generator 30.

FIG. 4 shows a support 23 intended to facilitate orientation of the EOD.The support 23 is provided with three bores 24, into which supportingrods 25 of any length and having predetermined breaking points 26 can beinserted.

As can be seen from FIG. 4, the support 23 allows the blast direction Sof the hollow charge 4 to be aimed towards the weapon to be destroyed.Through optimum use of the potential blasting power, large objects canalso be exploded by means of small EODs, in particular when the blastdirection S is aimed towards at least part of the detonating chain ofthe weapon.

Whereas in FIG. 1 a conical lining 3 made of industrial glass and easyto manufacture is used in conjunction with an explosive charge 2consisting of a well-known secondary explosive, in FIG. 5 aprojectile-forming, cup-shaped lining 3′ is provided.

For detonation of the explosive charge 2′, also consisting of octogen,an also known booster charge 22 consisting of hexogen (RDX) or octogen(HMX) is used, resulting in improved driving of the detonation wavetowards the highest point of the cup of the lining 3′.

The structure of the hollow charge 4′ corresponds substantially to thatof the above-described hollow charges 4 according to FIG. 1. However,for reasons of stability the ball support 12′ and the ball 13′ areattached to a circumferential clamping strap 21 on the cylindrical partof the hollow charge 4′.

FIG. 6 shows the temporal progress of the shaping process of the lining31. It can be seen from this that after 10 μs only a trace of the cupshape of the lining 3′ is left, and after 20 μs a projectile begins toform, which after 80 μs, i.e. after a distance of less than 12 cm,already has its final shape and has an extensive piercing effect, i.e. ahigh level of penetration in the target.

In the embodiments described, commercial plastics were used: thehousings 4, 4′ are made of glass-fibre-reinforced PBT(polybutylene-terephthalate); the covers 5, 5′ are also made ofglass-fibre-reinforced PBT; the housing of the detonator 28 is made ofPE (polyethylene) and the detonating tube 7 is made of a thin-walledaluminium sheet. Naturally, the detonating tube can also be made of POM(polyoxymethylene).

The support is made of POM and the rods 16 and 25 are made ofglass-fibre-reinforced PA6 (caprolactam polyamide).

For the detonation of anti-tank mines and other relatively large weaponsfrom distances of several metres, relatively large EODs have provedsuccessful, for example of 66 mm calibre. These were placed oncommercial camera or video tripods and aimed at the target over opensights (of a plastics strip).

In principle, all conceivable non-metallic, amorphous materials aresuitable for linings, although their economicalness and/or their densityset limits.

Linings made of technical glass (industrial glass) have proved to beoptimum because they can be manufactured inexpensively by a simplepressing process and are of a density which produces an adequatepiercing effect in the target.

Because, for logistical reasons, numerous mines of the same type areplanted in a given minefield, it is recommended for economical reasonsto use an EOD of which the calibre and lining are adapted to the minimumnecessary effect on the target. To increase the density and with it thepiercing effect, further known substances can be added to the glass. Inaddition to strontium, tellurium and minimal quantities of thallium alsoappear to fulfil the task.

Naturally, the subject of the invention is not limited to use inclearing mines, etc. Civil applications are also possible, e.g. inconnection with safety measures for pressure vessels, pipelines, etc.,i.e. in all cases where dangerous contamination by metals must notoccur.

The subject is also suitable for the remote-controlled detonation ofunidentified sabotage objects such as “explosive packages” etc. and caneasily be arranged on appropriate vehicles, from which they can be aimedand detonated.

What is claimed is:
 1. A device for the disposal of an explosive objectby producing in the explosive object an entrance opening into theexplosive object and introducing into the explosive object a destructivemechanism, comprising a piece of ammunition having a detonator in aplastic housing containing a hollow charge, a lining of the housingbeing supported in the plastic housing at a front end of the housing andan adjustable support mounted to the housing for aiming the piece ofammunition at the weapon to be disposed of, the lining being formed as aprojectile-forming charge and comprising a non-electrically conductive,amorphous material acting both to create the entrance opening andserving as the destructive mechanism without the introduction into theexplosive object of auxiliary reactive materials.
 2. A device accordingto claim 1, wherein the lining is cup-shaped.
 3. A device according toclaim 1 or 2, wherein the lining is made of glass.
 4. A device accordingto claim 1 or 2, wherein the lining is made of ceramic.
 5. A deviceaccording to claim 1 or 2, wherein the adjustable support has a ballprojecting from a cover of the plastic housing and, together with anattached socket, form a ball-and-socket joint connected to a rod.
 6. Adevice according to claim 5, further comprising a further support intowhich the rod with the ball-and-socket joint can be positively insertedand fixed.
 7. A device according to claim 6, wherein the further supporthas three supporting rods mounted in bores located in the furthersupport.
 8. A device according to claim 7, wherein the three supportingrods have predetermined breaking points over a major part of theirlengths.
 9. A device according to claim 1 or 2 wherein the lining issupported by supporting ribs arranged inside the housing at the frontend.
 10. A device according to claim 5, wherein the cover has an annulargroove into which a cylindrical part of the housing is inserted.
 11. Adevice according to claim 5, wherein the cover has a hollow cylindricalattachment into which the detonator is insertable.